San Francisco: Facebook Inc is looking to improve its search and indexing capabilities by adding the hashtag symbol, one of the most recognizable features of its social networking rival Twitter, according to media reports.

The hashtag, which appears as the # symbol, makes it easier for users to follow specific topics of conversation within the ever-changing stream of comments posted on Twitter. Users type the hashtag alongside a keyword - such as #election - at the end of a Tweet, making it easy to group comments on the same topic.

Facebook could similarly organize the conversations that take place on its more than one billon member social network by incorporating hashtags, said The Wall Street Journal which first reported the news on Thursday citing anonymous sources, thought it noted that the feature wasn't being introduced imminently. Facebook declined to comment.

Facebook introduced a revamped social search feature, dubbed Graph Search, in January. The search tool allows users to trawl their network of friends, as well as info shared publicly by other Facebook users, to find photos, interests and places, such as restaurants that are "liked" by people on Facebook.

The search tool does not currently allow users to search the contents of the actual conversations that are posted on Facebook. Hashtags could help Facebook make such searches possible, according to the technology blog TechCrunch, which also cited anonymous sources as saying such a feature was in the works.

It's not clear that searching the stream of Facebook comments would yield the breadth of results found on Twitter however. Unlike tweets, which are public and viewable to all users, most of the comments posted on Facebook are only viewable to a user's circle of friends.